Motor-controller.



No. 726,987. PATENTED MAY 5, l9 ()3.' W. B. POTTER. MOTOR CONTROLLER.

APPLICATION FILED AUG. 2, 1899.

N0 MODEL.

Fig.1.

Witnesses A Inventor.

7 William B. Patten 1 b v I p8 UNITED STATES Patented May 5, 1903. I

\VILLIAM B. POTTER, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO THEGENERALELEOTRIO COMPANY, A CORPORATION OF NEW YORK.

MOTOR-CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 726,987, dated May 5,1903.

Application filed August 2, 1899.

T0 aZZ whom it may concern:

Be it known that I, WILLIAM B. POTTER, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Motor-Controllers, ofwhich the following is a specification. 7

This invention relates to devices for controlling the application ofpower to motors. It is especially designed for railway service inconnection with electric motors where the rapid operation of thecircuit-controller in admitting current to the motor endangers thesafety of the apparatus, is extravagant in the use of current-,or causesjerky or unduly rapid acceleration.

The object of the invention is to provide a governing device positivelypreventing the too-rapid operation of the controller, or, in otherwords, a device which will force the operator or motorman to admitcurrent slowly through the controller by positively locking thecontroller against motion if the handle be turned too rapidly, but whichwill always permita rapid unobstructed movement between definiteperiods.

In carrying out theinvention I place in operative relation to thehand-operating device a locking-detent elastically connected to a movingpart and serving to insure a definite time interval or period of restbetween controller steps without interfering with the proper operationof the controller in passing from one step to another. Incar-controllers as commonly constructed the power-cylinder turned by themotormans handle when the motors are being connected into circuit isprovided with a star-wheel the undulating teeth of which are engaged bya spring-actuated pawl shod with a roller. By its efiect on the teeth ofthe star-wheel this pawl causes the controller-cylinder to move suddenlyfrom one position to another, thereby insuring a sudden rupture of thecircuits at the controller-contacts as the controller is moved from oneposition to another, as well as determining the position of rest at eachstep of the controller. I mount an auxiliary ratchetwheel having aseries of teeth on the same erial No. 725,852. orb model.)

axis as the star-wheel, and I connect to the pawl above mentioned anauxiliary pawlor detent movable with and controlled by the main pawl,but having a certain amount of free motionwith relation thereto andcapable of being impelled by its moment of inertia when the main pawlrides too rapidly over the inclines of the star-wheel into engagementwith the teeth of the ratchet-wheel, thus arresting the movement of themotormaus controllinghandle and positively preventing a too-rapidmovement of said controller through a series of steps. A time-limitretracting device for withdrawing the auxiliary pawl or detent fromengagement with the ratchet-wheel may also be provided, and by adjustingthis device the rate of enforced slow movement of-the controller may beva- -ried.

My in vention, although'as specifically embodied in the drawings of thisapplication shown applied to a controller for electric motors, is in itsmain features .of general application and capable of use with othermodes of transmitting power from a source to a motor driven by saidpower. Y

The invention in its broader aspect comprises a motor-controller capableof rapid and unobstructed movement between definite stages, butenforcing a slow movement through a series of such stages.

It comprises also a controller provided with a variabletime-limit devicefor adjusting the speed of application of power to the motor.

It comprises, further, means for enforcing a slow and gradualapplication of power by the movement of a detent brought into engagementwith a movable part of the controlling device by the force of inertiaunder rapid movement and means for varying itsmoment of inertia.

It comprises, further, other more specific features, which will behereinafter more fully described and will be definitely indicated in theclaims. v

In the drawingswhich illustrate one form of the invention, Figure 1 is atop plan view, with part of the cover broken away, of an electric-motorcontroller. Fig. 2 is an enlarged detail view of the device which limitsthe speed of application of power to the mo tor, showing also somemodifications in the details of construction. Fig. 3 shows a secondmodification of the speed-limiting device.

1 represents a star-wheel fast to the powercylinder of amotor-controller, the squared end of the shaft of which is indicated at2 and upon which is applied a handle manipulated by the motor-man. 3represents the shaft of a similar current-reversing cylinder. Theseveral teeth of the star-wheel correspond to the steps or positions ofthe controller, and in the particular controller indicated in thedrawings these steps operate to gradually cut out resistance and coupletwo or more motors from a condition of open circuit to a parallelrelation to the supply-circuit. The teeth of the star-wheel are engagedby a roller mounted on the end of a spring-retracted pawl 4, whichfollows the undulations in the periph cry of the star-wheel. With thisorganization, which is substantially that commonly provided incar-controllers, it is possible for the motorman to turn his controllerrapidly from a state of open circuit to the final condition ofadjustment of the motor-circuits, thereby giving an insuliicient timefor the motors to start up and endangering their safety by reason of thegreat rush of current, as well as subjecting the passengers toinconvenience and danger and all parts of the car to excessive strainsby reason of sudden jumps in acceleration. I provide a positive checkagainst such a sudden operation of the controllers by employing anauxiliary pawl or detent 5, which may be pivoted on the same axis as thepawl t and is connected to it by means of an elastic connection ortension device, such as a spring 6, the strength of which may be variedby an adjusting-nut, as indicated. The tip of this pawl cooperates witha ratchetwheel 7, mounted on the power-cylinder, and is so arrangedrelatively to the tip of the pawl 5 and the indentations of thestar-wheel that itsnotches will be in position to receive the pawl whenthe roller on the main pawl rests in a depression of the star-wheel. Thepawl 5 is provided withan adjustable weight 8, which may be shiftedalong a post and locked by a set-screw, so as to alter the moment ofinertia of the pawl about its pivot. Itis provided also with a retardingdevice by which its rapidity of retraction after engaging a tooth of thestar-wheel may be Varied. The spring 6 is capable of acting as avariable retractile force under the influence of theregulableadjListing-screw; but a more protracted time limit may beinsured by providing, as shown in the drawings, a dash-pot 9, into whichworks a plunger pivoted to the pawl. With this organization a rapidmovement of the controller-handle by the motorman permits theroller-shod pawl engaging the starwheel to drop quickly into one of thedepressions of the star'wheel, thereby. communicating a considerableimpulse to the pawl 5, which is free to obey the impulse, and distenrlsthe spring 6 and moves the plunger of the dash-pot, air entering througha leakopening in the plunger or wall of the dashpot, as indicated in thedrawings. On the next forward movement when the roller drops into theadjacent tooth of the star-wheel the pawl will be in position to engageone of the teeth of the ratchet-wheel,thereby locking the controlleragainst further movement until under the retractile force of the spring6 it is automatically unlocked, when the detent is drawn out ofengagement with the tooth. The rate of operation of this springconstituting the automatic unlocking device, and therefore the timeduring which the controller is locked, depends upon the moment ofinertia of the pawl or detent, the speed of leakage of the air trappedin the dash-pot, and the tension of the retracting spring.

The sensitiveness of operation may be increased hy providing thedash-pot with an inwardly-opening valve, permitting a rapid introductionof air upon forward movement of the plunger, but leaving only a smallopening on its rearward movement. This type of construction is shown inFig. 2, where a spring actuated inwardly opening checkvalve .10 isprovided, permitting a comparatively free admission of air to thecylinder on forward movement of the plunger, but leaving only a smallopening for the exit of air upon its backward movement. It is notabsolutely necessary to provide the dash-pot, although such a device orits equivalentai fords a convenient means of varying the length of timeduring which the arrest of the controller is effected.

With the construction above described it will be evident that wheneverthe controller is operated slowly its movement will be entirelyunobstructed as far as the locking device is concerned and, further,that it maybe operated as rapidly as desired between steps, but that themovement of the controller through a series of steps must necessarily besufficiently slow to permit the motor or motors to gradually acceleratein speed.

In Fig. 3 is shown an organization in which the dash-pot is dispensedwith. In this case the spring 6 brings the locking pawl or detentnormally into engagement with a lug or stop 11, mounted on theroller-shod pawl. When the controller is operated too rapidly, the speedof the roller-shod pawl toward the depressions in the star-wheel isimparted to the locking-pawl, and when the main pawl is arrested by thebottom of the groove of the star-wheel the inertia of the locking-pawlcarries it forward against the tension of the spring 6 into engagementwith a tooth of the ratchet-wheel, thereby arresting the movement of thecontroller-handle. It will be withdrawn with more or less quickness,according to the tensionot the spring 6, the momentum of the pawl, andits frictional engagement with the tooth of the ratchet-wheel, thelatter varying withthe shape of the nose of the pawl and the inclinationof the tooth.

It will thus be seen that with the apparatus herein described thecontroller can be adjusted for operation at any desired speed byshifting the adjusting-weight S and altering the tension of the spring6, thereby predetermining the rapidity with which the motorman can cutinto circuit the motors. It will be seen also that the length of timeduring which his movement can be arrested in case he applies the powertoo quickly can be definitely predetermined and adjusted by a change ofthe rate of leakage in the dash-pot or a change of the controllingdevices of the locking-pawl so as to alter its sensitiveness.

By my construction the controller may be operated rapidly withoutobstruction between the steps or operative positions of the controller,thus preventing damaging arcing at the contacts by permitting a quickrupture,

while the slow step-by-step movement necessary in order that the motorsmay gradually accelerate in speed is positively enforced.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. In combination, an electric controller having a series of operativepositions or steps, means for causing a sudden movement of the movablemember of the controller as it is moved from step to step, and means forposi tively preventing a rapid movement of said member through a seriesof'steps.

2. In combination, a controller having a series of operative positionsor steps, and a governing device constructed and arranged to permit arapid unobstructed movement between steps and to limit the speed ofmovement through a series of steps.

3. In combination, a controller, and a governing device elasticallyconnected to a moving part and operating by reason of its inertia topositively lock the controller against too rapid a movement.

4. In combination, a controller having a series of operative positionsor steps, and a governing device elastically connected to a moving partand operating by reason of its inertia to positively lock the controlleragainst too rapid a movement through a series of steps.

5. In combination, a controller, a governing device operatingautomatically upon too rapid a movement of the controller to positivelylock the said controller against movement, and a time-limit device forunlocking said governing device.

6. In combination, a controller, a speedcontrolled device for lockingsaid controller against movement, and a time-limit device for unlockingsaid controller.

7. In combination, a controller, a speedcontrolled device for lockingsaid controller against movement, and automatic means for unlocking saidcontroller.

8. In combination, a controller, a speedcontrolled device for lockingsaid controller against movement, automatic means for unlocking saidcontroller, and means for determining the rate of operation of saidautomeans.

11. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, andautomatic means for withdrawing said device, so as to permit furthermovement.

12. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, automaticmeans for withdrawing said device, and means for varying the moment ofinertia of said device.

13. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, automaticmeans for withdrawing said device, and means for varying the rate ofoperation of said automatic means.

14. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, automaticmeans for withdrawing said device, and means for determining the rate ofoperation of said automatic means. 4

15. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, and a springfor withdrawing said device, so as to permit further movement.

16. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, a spring forwithdrawing said device,and means for varying the moment of inertia ofsaid de- Vice.

17. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, a spring forwithdrawing said device,and means for varying the tension of saidspring.

18. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, a

spring for withdrawing said device,and means for determining therate atwhich said device is withdrawn.

19. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, a spring forwithdrawing said device,and means for controlling the operation of saidspring.

20. In combination, a controller, a device operating by reason of itsmoment of inertia to lock said controller against movement, a spring forwithdrawing said device, and a dash-pot for controlling the operation ofsaid spring.

21. In combination, a controller, a star Wheel mounted on saidcontroller, a spring-j actuated pawl engaging said star-wheel, a detentelastically connected to said pawl, and ai series of teeth on thecontroller in position to be engaged by said detent.

22. In combination, a controller, a star-1' wheel mounted on saidcontroller, a springactuated pawl engaging said star-wheel, a de-; tentelastically connected to said pawl, means; for varying the moment ofinertia of said de-. tent, and a series of teeth on the controller inposition to be engaged by said detent.

23. In combination, an electric controller, a star-wheel mounted on saidcontroller, a" spring actuated pawl engaging said starwheel, a detentelastically connected'tosaid: pawl, means for varying the tension ofsaid elastic connection, and a series of teeth on. the controller inposition -to be engaged by said detent.

24. In combination, an electric controller, a star-wheel mounted on saidcontroller, a springactuated pawl engaging said 'starwheel, a detent,operating by reason of its moment of inertia, elastically connected tosaid pawl, means for controlling the operation of said elasticconnection, and a series of teeth on the controller in position to beengaged by said detent.

25. In combination, an electric controller, a star-wheel mounted on saidcontroller, a springactuated pawl engaging said starwheel, a detent,operating by reason of its moment of inertia, elastically connected tosaid pawl, a dash-pot for controlling the operation of said elasticconnection, and a series of teeth on the controller in position to beengaged by said detent.

26. In combination a controller having aseries of operative positions orsteps, means for permitting a rapid'unobstructed movement of thecontroller between steps and a locking device for arresting such rapidmovement during the resting periods of such steps.

27. In a motor-controller, an elasticallymounted detent for arrestingmovement of the controller, and means for changing the moment of inertiaof said detent to regulate the speed of controlling the motor.

28. In a motor-controller, an elasticallymounted detent in operativerelation to the controller and brought into engagement there- 1 with byits inertia upon rapid operation of the controller, and means forimpelling said detent toward a clutching device on the controller whenthe latter is operated at an excessive speed. I

29. In a motor-controller, an elasticallymounted inertia-controlleddetent adapted to arrest the controller on rapid application of power tothe motor, and means for imparting a reciprocatory movement to thedetent, whereby momentum will be imparted to it upon rapid applicationof power.

30. In a motor-controller, an elasticallymounted detent in operativerelation to the controller and brought into engagement therewith by itsinertia upon rapid operation of the controller, means for impelling saiddetent toward a clutching device on the controller when the latter isoperated at an excessive speed, and means for retarding the backwardmovement of the detent with relation to the controller.

31. In a motor-controller, an elastically- -mounted detent'in operativerelation to the" controller and brought into engagement therewith by itsinertia, means for impelling said detent toward a clutching device onthe controller when the latter is operated at an excessive speed, and adash-pot for retarding the backward movement of the detent with relationto the controller.

32. In a motor-controller, an elasticallymo'unted detent in operativerelation to the controller and brought into engagement therewith by itsinertia upon rapid operation of the controller, means for impelling saiddetent toward a clutching device on the controller when the latter isoperated at an excessive speed, and an adjustable dash-pot for retardingthe backward movement of the detent relatively to the controller,whereby the time limit of its engagement may be controlled.

33. In a motor-controller, a series of undulating teeth connected to themovable member thereof, a yielding pawl bearing on said teeth, a movabledetent operated by said pawl, and aseries of teeth'in operative relationto said detent and adapted to be engaged thereby when the detent ismoved by rapid operation of the controller.

34:. In a motor-controller, a star-wheel, a pawl riding over said wheel,an elasticallymounted locking-detent controlled by said pawl and inoperative relation to a ratchetwheel in fixed relation to the controllerand adapted to lock the controller by its inertia, and a dash-potgoverning the rearward movement of said detent.

35. In a motor-controller, a star-wheel, a pawl riding over said wheel,an elasticallymounted locking-detent controlled by said pawl and inoperative relation to a ratchetwheel in fixed relation to the controllerand to said pawl, and a ratchet-wheel adapted to be engaged by saiddetent under the force of inertia when the controller is too rapidlyoperated.

In witness whereof I have hereunto set my hand this 31st dayof July,1899.

WILLIAM B. POTTER.

Witnesses:

BENJAMIN B. HULL, MABELVE. J ACOBSON.

